The digital authentication landscape stands at a critical juncture as two competing technologies—passkeys and cookies—reshape how users are authenticated, tracked, and engaged across the internet. While passkeys represent an innovative passwordless future designed to eliminate phishing vulnerabilities and simplify user authentication through biometric or device-based verification, cookies remain fundamental to how modern web applications function despite mounting privacy concerns and regulatory restrictions. This comprehensive analysis explores the fundamental differences between these technologies, examines how passkeys are emerging as alternatives to certain cookie functions, investigates the persistent security vulnerabilities that neither technology can fully eliminate, and clarifies why cookies continue to be essential infrastructure even as organizations increasingly adopt passkey-based authentication systems. The transition represents not a wholesale replacement but rather a complex reorganization of digital identity infrastructure, regulatory frameworks, and user privacy expectations that will define online interactions for years to come.
The Decline of Third-Party Cookies and the Privacy Regulatory Landscape
The era of unrestricted third-party cookie usage is definitively ending, driven by converging forces of regulatory action, consumer privacy concerns, and deliberate business decisions by major technology platforms. Third-party cookies have served for decades as the foundational technology enabling cross-site tracking, behavioral advertising, and personalized marketing campaigns that generate billions of dollars in digital advertising revenue. These small text files are placed on users’ browsers by websites other than the one being visited, allowing advertisers and analytics providers to follow users across multiple domains and compile comprehensive profiles of their browsing behavior. However, this ubiquitous surveillance mechanism has become increasingly untenable as governments worldwide have enacted stringent data protection laws requiring explicit user consent before tracking occurs.
The European Union’s ePrivacy Directive, enacted in 2009, represented the first major regulatory intervention against unrestricted cookie usage, establishing that websites must obtain affirmative consent from users before placing tracking cookies on their devices. This principle has been reinforced and strengthened through the General Data Protection Regulation (GDPR), which requires that consent be freely given, specific, informed, and unambiguous—criteria that have proven extraordinarily difficult for most websites to meet in practice. The GDPR’s enforcement has intensified significantly by 2025, with European regulators shifting from warnings to serious penalties for cookie consent violations, and recent regulatory actions targeting companies for manipulative cookie banner designs known as “dark patterns.” Sweden’s Data Protection Authority has become particularly aggressive in enforcement, making clear that organizations must implement technical solutions capable of blocking non-essential cookies before users grant consent, rather than simply displaying informational banners while cookies are already being set.
Beyond the EU, regulatory pressure has become global. The California Consumer Privacy Act (CCPA) and similar state-level privacy laws in the United States require that websites provide users with transparent information about data collection practices and offer mechanisms for opting out of data sales. Canada’s Personal Information Protection and Electronic Documents Act (PIPEDA), Japan’s Personal Information Protection Law (PIPL), and Brazil’s Lei Geral de Proteção de Dados Pessoais (LGPD) all impose varying requirements on cookie usage and tracking practices. This patchwork of regulations has created an environment where compliance with all applicable privacy laws often requires sophisticated consent management platforms capable of adapting cookie behavior based on users’ geographic location and regulatory context.
Simultaneously, major technology platforms have independently taken action to restrict third-party cookies, accelerating the decline of this technology independent of regulatory mandates. Apple’s Safari browser has blocked all third-party cookies by default since version 13.1 through its Intelligent Tracking Prevention (ITP) system, with no exceptions or workarounds available to users, fundamentally eliminating an entire advertising and tracking channel for many digital publishers. Mozilla Firefox implemented Total Cookie Protection, which partitions third-party cookies by site, meaning that while cookies may be set, they cannot be shared across different websites to enable cross-site tracking. Google announced an initial intention to phase out third-party cookies from Chrome by 2022, though this timeline has been repeatedly postponed through multiple delays in June 2021, July 2022, December 2023, and April 2024. In July 2024, Google clarified that it would not unilaterally deprecate third-party cookies but would instead offer user-choice controls allowing individuals to decide whether to block or allow third-party cookies globally, with enforcement of new privacy controls focused on Incognito mode where third-party cookies are already blocked by default.
This collective shift away from third-party cookies reflects fundamental recognition that the business models built around invisible, pervasive consumer surveillance have become incompatible with modern privacy expectations and regulatory frameworks. Companies are being forced to recognize that while cookies enabled enormously profitable personalization and advertising practices, the public externality of comprehensive behavioral tracking has become economically and politically unsustainable. The result has been a desperate search for alternative technologies that could maintain sufficient customer engagement and personalization capabilities while operating within new privacy constraints—a search that has led many organizations to consider passkeys as a potential component of a post-cookie digital identity infrastructure.
Passkeys as an Alternative Authentication Mechanism and Customer Engagement Tool
Passkeys represent a fundamentally different approach to user authentication compared to passwords, operating through public-key cryptography rather than shared secrets, and offering users a seamless biometric or device-based login experience that eliminates the need to remember, type, or manage complex credential strings. When a user creates a passkey with a website or application, the user’s device generates a public-private key pair; the website stores only the non-sensitive public key while the private key remains securely stored on the user’s device, typically in a secure enclave or trusted platform module (TPM) that prevents extraction even by sophisticated attackers. During authentication, the website issues a cryptographic challenge; the user’s device signs this challenge with the private key and returns only the signature, never transmitting the private key itself across the network. This architectural design eliminates numerous vulnerabilities inherent to password-based systems: attackers cannot intercept and reuse passkeys because they are cryptographically bound to specific websites, users cannot be phished into authenticating on fake sites because the browser and operating system ensure passkeys can only be used with their registered domain, and breaches of website databases cannot expose usable credentials because only public keys are stored.
From a user experience perspective, passkeys are dramatically simpler than traditional authentication methods, requiring only biometric verification such as a fingerprint or face scan, or alternatively a device unlock PIN, making authentication four times simpler than systems requiring one-time passwords. Amazon reports that users log in six times faster with passkeys compared to passwords, while TikTok users experience seventeen-fold login speed improvements. Microsoft reports sign-in success rates of 98 percent with passkeys compared to only 32 percent for traditional password-based authentication, reflecting the substantial friction that forgotten passwords, mistyped credentials, and account lockouts introduce into legacy systems. These performance improvements translate directly into business metrics: organizations implementing passkeys report reductions in authentication-related help desk calls of up to 70 percent, with authentication failures declining by 30 percent or more, and customer conversion improving through reduced cart abandonment when login friction is minimized.
The adoption trajectory for passkeys has accelerated dramatically as major platform providers—Apple, Google, and Microsoft—have built passkey support directly into their operating systems and browsers, making the technology accessible on virtually all modern devices without requiring specialized hardware or software installation. Google reports that over 800 million of its accounts now support passkeys, while Amazon’s first year of passkey deployment saw 175 million users creating passkeys for their accounts. The FIDO Alliance, the industry consortium driving passwordless authentication standards, reported that 48 percent of the top 100 global websites now support passkeys, with more than 100 organizations having made public commitments to adoption. Major consumer-facing platforms including PayPal, Shopify, Meta, TikTok, Best Buy, and Kayak have rolled out passkey authentication, making them accessible to hundreds of millions of users. In 2025, Bitwarden reported a 550 percent increase in daily passkey creation compared to the prior year, with users creating over one million new passkeys in just the final quarter of 2024. Authsignal’s analysis found that passkeys now account for 62 percent of authentication challenges in their systems, compared to only 33 percent for SMS one-time passwords, marking a historic inflection point where passkeys have overtaken legacy multi-factor authentication methods in real-world deployment.
However, the excitement surrounding passkeys has led many organizations to misunderstand the relationship between passkeys and cookies, creating confusion about whether passkeys can or should serve as comprehensive replacements for cookie-based functionality. While passkeys excel at solving the authentication problem—enabling users to prove their identity and gain access to accounts without the vulnerability of shared password secrets—they address only one component of digital identity infrastructure. Cookies, by contrast, serve multiple distinct functions that persist after authentication occurs, most critically the maintenance of authenticated sessions, personalization of user experiences, and the retention of state information across multiple page requests. Many organizations that have been enthusiastically adopting passkeys have simultaneously struggled to understand how their existing cookie-based infrastructure will function in a post-password world, and whether passkeys might somehow eliminate the need for cookies altogether. The answer, based on current technical architecture, is definitively no: passkeys cannot and should not replace the full functionality of cookies because the underlying technologies serve fundamentally different purposes in the architecture of web applications.
The Continued Necessity of Cookies: Session Management and the Persistent Authentication Challenge
Despite the regulatory pressure and privacy concerns driving restrictions on third-party tracking cookies, first-party cookies remain essential infrastructure that enables basic functionality of modern web applications and cannot be eliminated even as organizations widely adopt passkeys. After a user has successfully authenticated using a passkey, biometric verification, password, or any other authentication method, the server must maintain a record that the user has been authenticated for subsequent requests within that session; this is the purpose served by session cookies, which are small tokens stored in the browser that identify the authenticated user to the server without requiring re-authentication for every single page request or API call. Without session cookies, users would need to provide their authentication credentials for each action they take on a website, creating an unusable level of friction that would make modern web applications completely impractical.
First-party cookies set by websites on their own domain serve numerous essential functions beyond authentication, including storage of user preferences, maintenance of shopping carts during e-commerce transactions, tracking of form progress during multi-step processes, and persistence of accessibility settings for users with disabilities. These cookies represent legitimate application functionality rather than surveillance mechanisms, as they enhance usability by maintaining state information across sessions and preventing loss of user progress due to browser refreshes or temporary disconnections. Most regulatory frameworks, including GDPR and CCPA, implicitly recognize this distinction by categorizing first-party cookies for functional purposes as “necessary” cookies that do not require affirmative user consent prior to placement, distinguishing them from tracking cookies used for advertising and analytics which do require consent.
The fundamental point that security researchers and privacy advocates emphasize repeatedly is that the internet’s core technical architecture depends on cookies as a mechanism for implementing stateful sessions over the inherently stateless HTTP protocol. As SpyCloud, a prominent cybersecurity research organization, has stated bluntly: “Can we do away with cookies if they present such a huge risk? Frankly, no. Cookies are fundamental to the way the internet works.” This technical reality means that passkeys, despite their security advantages over passwords, cannot eliminate the need for cookies because they solve a different problem in the authentication and session management architecture. A user could authenticate using an extremely secure passkey and still require session cookies to maintain their authenticated state as they navigate through different pages of a web application, place items in shopping carts, or access personalized services. The two technologies operate at different layers of the digital identity and session management stack.
This architectural reality has profound implications for the transition away from password-based authentication toward passwordless systems. Organizations cannot simplistically replace their authentication infrastructure with passkeys and assume that the elimination of password handling will resolve their security and privacy obligations. Instead, they must recognize that modernizing authentication systems through passkey adoption represents one component of comprehensive security and privacy improvements that must simultaneously address the management of session cookies, the security of authenticated sessions, and the privacy implications of both authentication methods and session management mechanisms. The coexistence of passkeys and cookies in future digital infrastructure is not merely likely—it is technically inevitable given how modern web applications are architected.
Session Hijacking and the Fundamental Limitation of Authentication Technologies
While passkeys represent a significant security improvement over passwords in several important dimensions—most critically in their resistance to phishing attacks and prevention of credential reuse—they face a critical vulnerability that neither passkey advocates nor many security practitioners adequately emphasize: session hijacking attacks using stolen session cookies that completely bypass authentication mechanisms regardless of their strength. This attack vector represents what cybersecurity researchers term “next-generation account takeover” or “session hijacking,” and it fundamentally demonstrates that the strength of authentication methods becomes largely irrelevant once an attacker has compromised a user’s device and obtained access to valid session cookies.
Session hijacking works by exploiting the fundamental necessity of session cookies in web applications: after a user successfully authenticates using any method—whether passwords, multi-factor authentication, passkeys, or any other authentication mechanism—the server issues a session cookie that identifies the authenticated user for subsequent requests. These session cookies remain valid for extended periods, often hours, days, weeks, or even longer depending on how the application was configured, and they represent an already-authenticated session that does not require re-authentication with the original login credentials. When malware on a user’s device or browser extension steals these session cookies, an attacker can import them into an anti-detect browser—specialized software designed to mask the attacker’s true location, device characteristics, and behavioral patterns—and immediately gain all the permissions and access that the legitimate user possesses, without ever needing to know the user’s password, passkey, multi-factor authentication codes, or any other authentication credential.
SpyCloud, a cybersecurity company specializing in the recovery of malware-exfiltrated data, reported recapturing over 20 billion session cookies stolen by infostealers in a single year. These stolen cookies are actively traded on darknet marketplaces and used by cybercriminals to perpetrate account takeover attacks that take only seconds to execute and leave minimal forensic traces because they use valid, already-authenticated sessions rather than attempting to brute-force credentials or trigger authentication failures that would alert security systems. The attack is particularly insidious because session cookies typically do not raise security alarms when used—they are exactly the tokens that legitimate users use to maintain their sessions, so even sophisticated anomaly detection systems struggle to distinguish between a user’s authentic use of their own session and an attacker’s fraudulent use of a stolen cookie. This attack vector was starkly illustrated in the CircleCI breach, where attackers used malware to steal an employee’s two-factor authentication-backed single sign-on session token, then used that token to impersonate the employee and access the company’s internal systems, with the company’s antivirus software failing to detect the malware-infected state before the compromise occurred.
The critical security implication is that session hijacking completely renders passkeys irrelevant as a defense mechanism, despite passkeys’ status as phishing-resistant multi-factor authentication factors. A user could deploy the most sophisticated passkey implementation possible, complete with biometric verification, hardware security keys, and multiple layers of authentication, and an attacker with stolen session cookies still has immediate, unfettered access to all the user’s accounts and permissions. Session hijacking bypasses not only passkeys but also traditional multi-factor authentication, because the attack operates at the session layer rather than the authentication layer—it exploits the valid token that represents an already-completed authentication process rather than attempting to compromise the authentication process itself. The FBI’s Atlanta field office has specifically warned about this attack technique becoming increasingly prevalent among criminal organizations, emphasizing that multi-factor authentication, while still necessary and beneficial, cannot prevent session hijacking attacks.
The fundamental limitation this reveals is that no authentication method, regardless of how technically sophisticated, can protect against device compromise. If malware has successfully infiltrated a user’s device and gained access to the browser’s memory, local storage, or filesystem where session tokens are stored, authentication methods become irrelevant because the attacker operates from within an already-authenticated context. This means that the security model implicit in much passkey advocacy—the assumption that sufficiently strong authentication will protect user accounts from compromise—is fundamentally incomplete. Authentication strength matters greatly for preventing unauthorized access during the login process, but it becomes essentially meaningless when attackers bypass the login process entirely by stealing already-valid session credentials. The research and security community has begun recognizing this reality, with leading cybersecurity organizations emphasizing that “device-level compromise, not credential theft, is becoming the dominant driver of identity risk” and arguing that security strategies focused exclusively on the login layer miss the more consequential threat of post-authentication session compromise.
Privacy Implications: Passkeys and Cookies in Comparative Analysis
The privacy characteristics of passkeys and cookies differ substantially, reflecting their fundamentally different technological architectures and purposes, but neither technology is inherently privacy-preserving and each presents distinct privacy considerations that users and organizations must understand. Passkeys, when implemented according to specifications, offer several privacy advantages over cookies and certain other authentication methods: since biometric data never leaves a user’s device but is only used locally to unlock cryptographic credentials, websites never receive or store sensitive information about the user’s fingerprint, face scan, or other biometric data. The private keys underlying passkeys are typically end-to-end encrypted when synced across multiple devices through cloud-based keychains such as Apple’s iCloud Keychain or Google Password Manager, meaning that even the cloud provider cannot access, view, or extract the passkeys. Unlike social login systems that require users to authenticate through Google, Apple, or similar providers, which enables those companies to track which websites and applications a user visits and engages with, creating a comprehensive cross-site behavioral profile, each passkey is unique to a specific website, preventing tracking across different sites.
However, passkeys do present some privacy considerations that deserve attention. If a user stores passkeys in a security key or trusted platform module, websites can potentially request the make and model of the device used for authentication, which could theoretically enable some form of device fingerprinting for tracking purposes, though browsers have implemented policies requiring that each distinct make and model represent at least 100,000 devices to prevent uniquely identifying individuals. If passkeys are stored in cloud-synced password managers, websites can infer which password manager a user employs, potentially enabling some inference about user software choices. Some security key implementations maintain a “signature counter” for tracking purposes, though proper implementations should maintain separate counters for each site to prevent cross-site correlation. More importantly, while passkeys themselves prevent tracking between sites through unique credentials per service, they do not prevent a website from tracking users if that website chooses to do so; passkeys eliminate the possibility of cross-site tracking but do not eliminate first-party tracking by individual websites.
Cookies present a more complex privacy landscape that varies dramatically depending on whether they are first-party cookies set by the website a user is visiting or third-party cookies set by external domains such as advertising networks and analytics providers. First-party cookies are generally privacy-neutral when used for functional purposes such as session management, user preferences, and shopping cart state, as they merely enable the website to remember information the user has explicitly provided. Third-party tracking cookies, by contrast, enable systematic surveillance where advertising networks and analytics providers track users across hundreds or thousands of websites, compiling detailed profiles of browsing behavior, interests, search history, and purchasing patterns. These comprehensive behavioral profiles are the economic foundation of the targeted advertising industry and represent a significant privacy intrusion that is entirely different from the privacy implications of passkeys or first-party functional cookies.
The key distinction for privacy analysis is between tracking cookies and necessary cookies: tracking cookies are designed specifically to follow users across multiple websites and sites to enable behavioral profiling and targeted advertising, creating privacy risks that are qualitatively different from functional cookies that merely enable basic web application features. Regulatory frameworks reflect this distinction by permitting necessary cookies without requiring prior consent while mandating affirmative opt-in consent for tracking cookies. The privacy advantage that passkeys offer relative to cookies is therefore primarily relevant in comparison to third-party tracking cookies rather than first-party functional cookies, and the two technologies are addressing fundamentally different privacy problems: passkeys solve the authentication privacy problem by preventing phishing and credential theft, while cookie restrictions address the tracking privacy problem by preventing systematic surveillance across multiple websites.
A comprehensive privacy approach requires managing both technologies effectively: users and organizations need strong authentication mechanisms like passkeys that prevent compromised credentials and phishing attacks, and they simultaneously need robust cookie management that restricts third-party tracking and minimizes unnecessary data collection through first-party cookies. The privacy transition should not be conceptualized as passkeys replacing cookies, but rather as a simultaneous evolution of both authentication mechanisms and cookie policies, with passkeys supporting strong authentication while enhanced cookie controls restrict tracking. This reflects what privacy advocates argue should be a “privacy by design” approach where both technologies are implemented with privacy as a fundamental principle rather than an afterthought.
Regulatory Compliance and the Evolution of Authentication Standards
Regulatory frameworks are increasingly mandating specific authentication standards and cookie management practices, creating a complex compliance landscape that organizations must navigate to operate legally across different jurisdictions while simultaneously maintaining user trust and security. The regulatory environment for authentication has shifted dramatically toward requiring phishing-resistant authentication methods, most notably through the U.S. National Institute of Standards and Technology’s 2025 update to its authentication guidelines, which mandates that all federal agencies adopt phishing-resistant multi-factor authentication including standards like WebAuthn and FIDO2 that underlie passkey implementations. This federal requirement for passkeys in government systems represents official recognition of passkeys’ security advantages and has created important upstream pressure on regulated industries such as financial services, healthcare, and defense contractors that work with government agencies and must achieve compliance with NIST standards.
The European Union’s regulatory framework, particularly through GDPR and the ePrivacy Directive, has become increasingly stringent in 2025, with regulators moving from general warnings to specific enforcement actions targeting organizations that fail to implement compliant cookie consent mechanisms. The regulatory focus has shifted toward “prior consent” implementation, requiring that technical systems actually block non-essential cookies from being set or executed until users have explicitly opted into them, rather than merely displaying informational banners while cookies load automatically. This technical enforcement requirement means that cookie consent management is no longer a legal and privacy policy matter but has become a technical infrastructure requirement that organizations must implement through specialized consent management platforms capable of intercepting and blocking cookie and script execution until proper consent has been obtained. Sweden’s Data Protection Authority has become particularly aggressive in enforcing these requirements, with regulators examining not only what users see in cookie banners but also the technical behavior of websites to verify that non-essential cookies are actually being blocked prior to consent.
For authentication specifically, PSD2 (Payment Services Directive 2) in the European Union has mandated strong customer authentication for financial transactions, which has accelerated passkey adoption in the banking sector as institutions seek phishing-resistant authentication methods that can provide the required security guarantees while maintaining acceptable user experience. The Banking Standard (BS) regulatory regime in certain jurisdictions and the Monetary Authority of Singapore’s Transaction Risk Management guidelines have similarly pushed financial institutions toward passkey adoption to meet regulatory security requirements. Organizations in financial services are actively developing what researchers term “Passkeys+” implementations that add additional controls beyond standard passkey specifications, including device binding to ensure passkeys remain anchored to known, trusted devices rather than being synced to the cloud, context-aware authentication checks that require re-authentication for high-value transactions, and stronger session assurance controls that detect and respond to suspicious authentication patterns.
The California Consumer Privacy Act (CCPA) and similar state-level U.S. privacy laws require data minimization principles and strong security measures, creating incentives for passkey adoption because passkeys fundamentally reduce the amount of authentication data that must be stored and managed compared to password-based systems. Organizations implementing passkeys in CCPA-subject contexts benefit from significantly reduced data storage requirements, as they need only store public keys rather than password hashes or other authentication credentials. However, full CCPA compliance with passkeys requires implementation of the Credential Exchange Protocol (CXP), which is currently in draft status at the FIDO Alliance and would enable users to port their passkeys between services, supporting the CCPA’s data portability requirements. Until CXP is formally published, organizations cannot claim complete CCPA compliance if their authentication systems lack portability mechanisms.
This evolving regulatory landscape creates complex compliance obligations where organizations must simultaneously implement phishing-resistant authentication mechanisms to meet emerging standards like NIST guidelines, ensure prior consent for non-essential cookies to meet GDPR requirements, implement cookie blocking technical infrastructure to satisfy European Data Protection Authority enforcement expectations, and potentially adopt Passkeys+ with additional security controls to meet financial regulation requirements in relevant jurisdictions. The result is that compliance with authentication and privacy regulations has become a substantial technical challenge requiring coordinated security, engineering, and privacy teams to design systems that satisfy multiple overlapping regulatory regimes while maintaining acceptable user experience and operational efficiency.
Cross-Platform Implementation Challenges and the Fragmented Passkey Ecosystem
Despite the enthusiasm around passkeys and their availability across major platforms, the practical reality of implementing passkeys consistently across browsers, operating systems, and devices remains significantly more complex than marketing materials suggest, creating user experience challenges that persist as substantial barriers to mainstream adoption. The core problem is that while Apple, Google, and Microsoft have all committed to passkey support, their implementations diverge in consequential ways that create confusion and friction for users attempting to use passkeys across multiple devices or in less common computing environments. Users cannot reliably use passkeys consistently across platforms because the experience differs substantially depending on whether they are using Safari on iOS, Chrome on Android, Edge on Windows, or Firefox on Linux, with each browser-platform combination implementing passkey support differently based on the particular ecosystem’s architectural choices and business incentives.
The architectural fragmentation stems from the fact that each major platform provider has strong incentives to encourage users to store their passkeys within their own ecosystem’s keychain or password manager system, whether Apple’s iCloud Keychain, Google’s Password Manager, or Microsoft’s authenticator implementations. This creates a situation where users who store their passkeys in Apple’s iCloud Keychain can use them seamlessly across all their Apple devices but face significant friction when attempting to authenticate on non-Apple devices, while users who partition their passkeys across multiple providers must maintain awareness of where each passkey is stored and which devices have access to which passkeys. For developers and organizations attempting to implement passkey authentication, this means supporting multiple different passkey creation and authentication flows depending on the user’s device type and browser, requiring technical teams to understand and accommodate the divergent implementations of different platform providers.
The user experience challenges created by this fragmentation are substantial. Users frequently cannot determine which passkeys they have created, whether they are synced across devices, or whether they are stored in local device storage or cloud-synced keychains. When attempting to log into a website, users may see inconsistent options for using passkeys depending on their current device, with passkeys that exist on one device not available on another without explicitly syncing them. For users switching devices or accessing systems from different locations, the experience is often confusing, requiring them to navigate recovery processes or fall back to traditional password authentication if they cannot access the appropriate device containing their passkey. Organizations attempting to promote passkey adoption report that users frequently abandon the passkey setup process because the enrollment flow is unclear or because they lack understanding of how to use passkeys consistently across their multiple devices.
Additional cross-platform inconsistencies emerge around the distinction between synced and device-local passkeys. Google’s implementation allows users to create passkeys that are stored locally on the device where they are created, but these local passkeys are not automatically available on other devices; instead, Google creates a separate passkey on each device. Apple’s implementation syncs passkeys across all devices associated with the same iCloud account, meaning a user needs only one passkey on their primary device. Microsoft’s approach for Windows-synced passkeys was introduced in 2025 and provides synchronization similar to Apple’s model. These architectural differences mean that the recovery experience for users who lose devices or need to authenticate on new devices differs substantially across platforms, with implications for usability and accessibility.
The browser variability also creates implementation complexity. Safari’s Intelligent Tracking Prevention system blocks third-party cookies entirely, but the Storage Access API allows websites and iframes to request user permission to access first-party storage under specific circumstances, creating a nuanced permission model that does not exist in other browsers. Firefox’s Total Cookie Protection partitions cookies rather than blocking them, allowing third-party cookies to be set and read but only within the context of the specific top-level site where they originated, meaning third-party cookies cannot be used for cross-site tracking but can still be used for legitimate embedded functionality. Chrome maintains no automatic cookie partitioning but allows third-party cookies to be blocked globally through user settings or policies. These divergent approaches to cookie handling create implementation challenges for organizations attempting to deploy authentication systems that work reliably across browsers, as they must account for different cookie behaviors in different browsers when implementing session management and other cookie-dependent functionality.
The Coexistence Model: Why Passkeys and Cookies Will Persist Together
The evidence from regulatory trends, technology adoption patterns, and technical architecture analysis indicates that passkeys and cookies will coexist in future digital infrastructure for the foreseeable future, not because this is the optimal solution but because the technical, economic, and practical realities of the internet’s evolution dictate this outcome. This coexistence model represents not a temporary transitional state but a stable equilibrium where passkeys handle authentication functions while cookies continue managing session state, user preferences, and application-level state information. Understanding this coexistence as permanent is essential for organizations attempting to modernize their authentication infrastructure, as it means investments in passkey adoption should be conceptualized as complementary to improved cookie management rather than as a replacement strategy.
The economic and practical factors supporting coexistence are substantial. First-party cookies have become deeply embedded in web application architecture across literally trillions of websites and applications built over decades, making them too fundamental to replace without a complete redesign of how the internet works. Replacing cookies with entirely new session management mechanisms would require coordinated effort across all browsers, all websites, and all web developers globally—a level of coordination that has never been achieved for such a fundamental infrastructure component. The existing cookie infrastructure, despite its age and various limitations, works adequately for session management purposes once third-party tracking is restricted through appropriate regulatory enforcement and browser-level protections. The regulatory trends indicate acceptance that cookies are necessary infrastructure, with regulations focused on restricting tracking cookies rather than eliminating cookies entirely, reflecting recognition that first-party cookies serve essential functions that cannot easily be replaced.
Second, the regulatory landscape has not mandated replacement of cookies but rather restriction of third-party tracking and enforcement of consent requirements before third-party cookies are placed. The GDPR’s requirements focus on categorizing cookies appropriately and obtaining proper consent for tracking cookies, not on eliminating cookies from digital infrastructure. The ePrivacy Directive similarly requires consent for tracking but permits necessary cookies without requiring prior consent. Even in the most privacy-focused regulatory frameworks, cookies are recognized as necessary infrastructure that should be managed and controlled rather than eliminated. This regulatory approach implicitly accepts the coexistence model, requiring only that organizations implement cookie controls and consent mechanisms while maintaining cookie functionality for necessary purposes.
Third, from the perspective of user experience and business outcomes, the combination of passkeys for authentication and well-managed cookies for session state and personalization provides superior functionality compared to either technology alone. Passkeys enable fast, secure, phishing-resistant authentication that eliminates password friction while reducing support costs for authentication-related issues. Once users are authenticated, cookies enable seamless, stateful experiences where users do not repeatedly re-authenticate, shopping carts maintain items across browsing sessions, and user preferences persist without requiring explicit restoration on each visit. Attempting to eliminate cookies entirely would require rebuilding this functionality through different mechanisms, a technically complex endeavor that would likely result in worse user experience during the transition period and may not ultimately provide meaningful privacy benefits if alternative technologies enabling session state and personalization are developed to replace cookies’ functionality.
The evidence of coexistence is already visible in mainstream adoption patterns: major organizations that have been most enthusiastically adopting passkeys are simultaneously implementing enhanced cookie management systems, consent management platforms, and cookie-blocking technical infrastructure to comply with privacy regulations. These organizations recognize that passkeys and cookie management address different problems and both require sophisticated implementation. Financial institutions deploying Passkeys+ are not using this as a reason to eliminate cookies but rather to supplement cookie-based session management with additional security controls around high-value transactions. E-commerce platforms adopting passkeys for authentication are not eliminating shopping cart cookies but are using passkeys to reduce login friction while maintaining cookie-based cart functionality. This indicates that organizational leaders implementing modern authentication systems understand at a practical level that passkeys and cookies serve complementary functions and that investment in both technologies simultaneously is necessary for comprehensive modernization of digital identity infrastructure.
The Path Forward: Strategic Implications and Implementation Recommendations
Organizations attempting to modernize their authentication and identity infrastructure should recognize that the transition to passkeys represents an evolution of the digital identity stack rather than a wholesale replacement of existing technologies. This understanding has important strategic implications for how organizations should structure their identity and security investments, what timelines are realistic for adoption, and how to manage the complex technical transition from password-dominant to passkey-dominant authentication while simultaneously implementing enhanced cookie controls and session management.
The first implication is that passkey adoption should be pursued as a phasing in of new authentication options alongside existing authentication methods rather than an attempt to sunset passwords and existing multi-factor authentication entirely. Organizations should implement passkey creation flows that make it easy for users to enroll without requiring immediate abandonment of existing authentication methods, as users typically need multiple months of familiarity and repeated successful usage experiences before they develop confidence in new authentication mechanisms. Organizations should monitor adoption metrics and user experience feedback to identify barriers to passkey creation and usage, using this feedback to refine onboarding flows, user documentation, and support processes to reduce friction that prevents adoption. This gradual transition approach reduces the support burden that would result from forcing all users to passkeys simultaneously while still enabling the benefits of passkey adoption to accrue as increasing user populations embrace the new technology.
The second implication is that passkey adoption must be accompanied by parallel investment in enhanced cookie management, consent infrastructure, and session security to ensure that the authentication modernization is part of a comprehensive privacy and security strategy rather than a siloed technology initiative. Organizations should implement consent management platforms capable of categorizing cookies appropriately, blocking non-essential cookies until consent is obtained, and documenting consent decisions for audit purposes, ensuring compliance with GDPR, ePrivacy Directive, and other applicable regulations. Organizations should simultaneously implement enhanced session management controls including reasonable session timeout periods, device fingerprinting and anomaly detection to identify suspicious session usage patterns, and session-layer security that detects and responds to potential session hijacking attempts. These session management improvements address the session hijacking vulnerability that defeats even strong authentication, recognizing that the strength of authentication is incomplete without parallel protection of authenticated sessions.
Third, organizations should recognize that the ecosystem fragmentation around passkeys requires deliberate strategies for supporting users across diverse devices and browsers. Organizations should audit their authentication flows across multiple browsers and device types to identify where the user experience diverges, prioritizing fixes for the most commonly used combinations while documenting requirements for less common device-browser combinations. Organizations should invest in user education and clear documentation explaining how passkeys work across different devices, what to do when passkeys are not available on a particular device, and how to recover access if primary devices are lost. Organizations should also engage with standards bodies and platform providers through industry associations like the FIDO Alliance to advocate for consistency across passkey implementations, recognizing that standards convergence is essential for the ecosystem to move beyond current fragmentation challenges.
Fourth, organizations in regulated industries such as financial services, healthcare, and government should monitor evolving regulatory requirements around authentication and proactively implement compliance-ahead authentication systems that exceed current minimum requirements. Financial institutions should recognize that regulators are increasingly mandating phishing-resistant authentication and should plan to deploy Passkeys+ or similar enhanced implementations that provide the additional security controls expected to become standard regulatory requirements. Organizations subject to NIST guidelines should treat the 2025 federal mandate for phishing-resistant multi-factor authentication as a signal that equivalent requirements will expand across regulated industries and should begin planning deployment accordingly. Organizations in GDPR and ePrivacy Directive jurisdictions should recognize that regulatory enforcement is intensifying and should implement prior-consent cookie blocking rather than treating cookie consent as a legal compliance checkbox.
Finally, organizations should recognize that session hijacking and device compromise represent increasingly important threats that require security strategies beyond authentication. Organizations should implement post-infection remediation approaches that detect when user credentials and session tokens have been exposed through malware, enabling rapid invalidation of compromised sessions and devices even when the user’s authentication credentials remain uncompromised. Organizations should invest in threat intelligence capabilities that track whether their users’ credentials appear in breach databases and malware-exfiltrated data available on darknet markets, using this intelligence to identify compromised users and trigger remediation processes. These approaches recognize that authentication strength alone cannot protect against device compromise and that comprehensive identity security requires monitoring for evidence of compromise alongside efforts to strengthen authentication mechanisms.
The New Digital Blueprint
The digital authentication landscape is undergoing a significant transition, but not the wholesale replacement of technology commonly implied by the “passwordless future” narrative. Rather, the transition represents a sophisticated reorganization where passkeys supplement and gradually replace passwords as the primary authentication mechanism, while enhanced cookie management implements privacy controls over third-party tracking, and robust session management protects against session hijacking attacks. This multidimensional transition is driven by converging pressures: regulatory mandates requiring privacy-preserving authentication, business recognition that passwords create unacceptable friction and support costs, technological innovation enabling passkeys to work across major platforms, and security research revealing that both authentication strength and session security are necessary for comprehensive identity protection.
Passkeys represent a genuine security and usability improvement over passwords, offering phishing resistance, elimination of credential reuse vulnerability, dramatically simplified user experience, and significant reductions in authentication-related support costs. The rapid adoption of passkeys by major platforms and mainstream organizations indicates that this technology has crossed from innovative curiosity into practical infrastructure that will continue expanding in use. However, the passkey transition should not be conceptualized as a solution to cookie-related privacy problems, as the two technologies address fundamentally different challenges in digital identity infrastructure. Passkeys solve the authentication problem by preventing phishing and credential theft, while cookie management addresses the tracking problem by restricting cross-site behavioral surveillance. Both challenges require attention and both solutions are essential for comprehensive improvements to digital privacy and security.
The regulatory environment is increasingly mandating specific authentication standards and cookie management practices, creating a complex but clear compliance imperative for organizations to implement passkeys while simultaneously enhancing cookie controls. The European Union’s increasingly aggressive enforcement of prior-consent cookie requirements demonstrates that regulatory pressure will intensify rather than diminish, making compliance ahead of regulatory actions a prudent business strategy. The U.S. federal mandate for phishing-resistant multi-factor authentication signals that equivalent requirements will expand across regulated industries, making early passkey adoption a competitive advantage and risk mitigation strategy. Organizations that delay implementing passkeys and enhanced cookie controls are likely to face regulatory pressure, competitive disadvantage as users migrate to platforms offering better authentication and privacy experiences, and security incidents arising from exploitation of outdated authentication mechanisms and unmanaged session hijacking vulnerabilities.
The critical insight is that the future of digital authentication is not a choice between passkeys and cookies, but rather a sophisticated system where passkeys provide strong, phishing-resistant authentication that replaces password-based login, first-party cookies maintain session state and application functionality, tracking cookies are eliminated or heavily restricted through regulatory compliance and browser protections, and enhanced session management detects and prevents session hijacking attacks that bypass authentication strength. This coexistence model reflects technical realities of how the internet operates, regulatory acceptance that cookies are necessary infrastructure requiring control rather than elimination, and practical recognition that no single technology solves all identity and privacy challenges simultaneously. Organizations that understand this multidimensional transition and implement comprehensive solutions addressing authentication modernization, cookie management, privacy compliance, and session security will position themselves as leaders in the evolving digital identity landscape while building sustainable competitive advantages in customer trust and operational efficiency.
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